Control system for conveying apparatus

ABSTRACT

A control system for a conveying apparatus of a type consisting of one or more independently movable carriages supported on a rail extending along a series of treating stations, and wherein each carriage has one or more independently movable lift mechanisms thereon for depositing and removing racks with workpieces at the stations. In one embodiment, the programming device on the carriage for providing sequentially-phased movement of the carriage and lift mechanisms is advanced by a transferring motor which is actuated in response to the tripping of sensing devices on the carriage indicating the position of the carriage relative to the stations and the up and down position of the lift mechanism. The programming devices of each carriage, if a plurality of carriages are used, are interlocked to maintain them in sequence and a timer is employed to control portions of the operating cycle duration. In an alternate embodiment, the advancement of the programming device is achieved electronically in response to the carriage travel and the tripping of the lift mechanism sensing devices.

United States Patent [191 Brian Oct. 9, 1973 CONTROL SYSTEM FOR CONVEYING APPARATUS [57] ABSTRACT [75] Inventor: Michael A. Brian, St. Clair Shores, A control system for a conveying apparatus of a type Mich. consisting of one or more independently movable car- [73] Assignee: The Udylite Corporation, Warren, nageF suppqrted on a tall ixtendmg alfmg a of treating stations, and wherein each carnage has one or MlCl'l.

more Independently movable 11ft mechanisms thereon [22] Filed: Mar. 10, 1971 for depositing and removing racks with workpieces at [2]] Appl. No.: 122,820

Primary Examiner-Paul J. Henon Assistant Examiner-Mark Edward Nusbaum Attorney-Harness, Dickey & Pierce w a] g 7/ if g the stations. In one embodiment, the programming device on the carriage for providing sequentially-phased movement of the carriage and lift mechanisms is advanced by a transferring motor which is actuated in response to the tripping of sensing devices on the carriage indicating the position of the carriage relative to the stations and the up and down position of the lift mechanism.

The programming devices of each carriage, if a plurality of carriages are used, are interlocked to maintain them in sequence and a timer is employed to control portions of the operating cycle duration. In an alternate embodiment, the advancement of the programming device is achieved electronically in response to the carriage travel and the tripping of the lift mechanism sensing devices.

37 Claims, 45 Drawing Figures PATENTED OCT 9 5 sum 03 or as PATENTEU w 9 m3 sum as or as INVENTOR.

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PAIENIED 9 saw us nr 3 PATENTEDDBT 9 I973 sum 13 or as PATENTED 9 73 sum laws; 

1. A control system for an electrochemical workpiece processing apparatus, including programming means, having a tape reader, wherein the workpiece is sequenced between or among a plurality of work stations in response to commands generated by the programming means, the apparatus including transfer and lift means for moving the workpiece in a transverse and vertical direction between or among the work stations, the improvement comprising tape program storage means associated with said programming means for generating the commands to sequence the workpiece, the tape reader including means for stepping said tape means sequentially through a sequence of commands in said program storage means, means indicating the position of the workpiece, and condition circuit means connected to said indicating means for sensing at least the position of the workpiece and the completion by the apparatus of the commands generated by the program storage means and generating a condition signal for controlling the programming means, said stepping means including control circuit means for stepping said programming means through said sequence of said program storage means at least in response to said condition signal.
 2. The system of claim 1 further including clock circuit means generating periodically spaced pulses for stepping the programming means in response to said pulses, said pulses occurring as a continuous stream.
 3. The system of claim 2 wherein said control circuit means includes an and-function gate having an input circuit connected to said clock pulse means for controlling the feeding of said stepping pulses to said programming means.
 4. The system of claim 3 wherein said system further includes at least an automatic mode of operation, said gate means including input circuit means responsive to said automatic mode of operation.
 5. The system of claim 4 wherein said control circuit means includes automatic mode storage means having a first and second state, the switching of said control system to said automatic mode causing said storage means to be in said first state, said first state enabling said gate means to pass said clock pulses.
 6. The system of claim 5 further including output gate means having at least a first and second input including an input from said automatic and-function gate and a second input from a manual and-function gate, both said and-function gates receiving input pulses from said clock pulse circuit.
 7. The system of claim 6 wherein said system includes a manual function circuit for sensing when said system is in the manual mode, manual and-function gate includes the input from said clock pulse circuit means and an input from the manual function circuit, said manual function circuit having bistable storage means for storing when the control system is in the manual mode of operation.
 8. The system of claim 7 wherein said clock pulse circuit means steps the programming means in response to said clock pulses when the system is in the manual mode of operation.
 9. The system of claim 5 wherein said condition circuit means includes condition gate means for sensing when said workpiece has been sequenced to a preselected work station, said condition signal disabling said automatic storage means when said preselected station has been commanded but not achieved, and enabling said storage means when said preselected station is achieved.
 10. The system of claim 9 further including means for sensing the vertical lift condition of the apparatus and means for sensing other conditions, and wherein said condition gate means includes at least three inputs, one of said inputs being from said station sensing means, a second input from said lift sensing means and a third input from said means for sensing other functions of the apparatus for accomplishing plating of said workpiece, said condition signal being generated in response to the sensing of one of the achieving of the preselected station, the completion of the lift signal and the completion of the other functions of the apparatus.
 11. The system of claim 10 wherein said programmed storage means includes a plurality of combination commands designating at least one of left to a preselected address, right to a preselected address, up to a preselected elevation, down to a preselected elevation and other timing and interlock functions, the improvement further comprising a step number counter for storing and providing an indication of the number of combination commands which have been sensed in the programming means from a preselected position on the programmed storage means.
 12. The system of claim 11 further including means for stepping said step number counter in response to a coincidence of said combination command and said periodically spaced pulses.
 13. The system of claim 12 further including coded reset commands for resetting said step number counter circuit in response to the sensing of said reset command in said programming means, said reset code occuring adjacent said preselected position on said program storage means.
 14. The system of claim 12, wherein said reset code is a single letter code having a multi-channel bit count, a gate connected to receive said mUlti-bit count and produce an output signal in response thereto, the output of said gate being fed to the reset circuit of said step number counter.
 15. The system of claim 14 further including visual lamp indicators for indicating the step number from the preselected position on said program storage means, the output of said step number counter energizing said indicating means.
 16. A method of controlling an electrochemical workpiece processing apparatus including sequencing the workpiece between or among a plurality of work stations in response to generated commands, the apparatus including programming means for generating the command, and transfer and lift means for moving the work piece in a transverse and vertical direction, the method comprising the steps of generating the commands to sequence the transfer and lift means between and among the work stations, stepping said programming means sequentially through a sequence of commands, indicating the transfer and lift positions of the workpiece, and sensing at least the position of the workpiece and the completion by the apparatus of the commands generated by the programming means, and generating a condition signal for controlling the programming means, said stepping of said programming means being unidirectional and through said sequence of said program storage means at least in response to said condition signal.
 17. The method of claim 16 further including the step of generating periodically spaced pulses for stepping the programming means in response to said pulses, said pulses occurring as a continuous stream.
 18. The method of claim 17 further including the step of controlling the feeding of said stepping pulses to said programming means by enabling and disabling a gate circuit.
 19. The method of claim 18 wherein the apparatus includes an automatic mode of operation, the method further including the step of switching said apparatus to said automatic mode, said switching step causing said enabling of the gate circuit to pass said clock pulses.
 20. The method of claim 19 wherein the apparatus includes a manual mode of operation selected by a manual button, the method further including the step of stepping the programming means in response to said clock pulses when the system is in the manual mode of operation.
 21. The method of claim 19 further including sensing when said workpiece has been sequenced to a preselected work station and disabling said clock pulses when said preselected station has been commanded but not achieved, and enabling said clock pulses when said preselected station is achieved.
 22. The method of claim 21 wherein said method further includes sensing when the work piece has been lifted to a preselected height and other functions of the apparatus for plating of the workpiece, said condition signal being generated in response to the sensing of one of the achieving of the preselected station, the completion of the lift signal and the completion of the other condition signals.
 23. The method of claim 22 wherein said program storage means includes a plurality of combination commands designating at least one of left to a preselected address, right to a preselected address, up to a preselected elevation, down to a preselected elevation and other timing and interlock functions, the method further comprising counting and providing an indication of the number of combination commands which have been sensed in the programming means from a preselected command.
 24. The method of claim 23 further including stepping said step number counter in response to a coincidence of said combination command and said periodically spaced pulses.
 25. A control system for an electrochemical workpiece processing apparatus including a workpiece carrier, and programming means wherein the workpiece is sequenced through a plurality of work stations in response to commands generated by the programming means, the improvement comprising a two-speed transfer means for moving the workpiecE in a transverse direction through said work stations, means for generating a command to direct the workpiece apparatus to transfer to the right or left to a selected station designated by a coded address, said means for generating including the programming means, means for sensing when said apparatus has approached a preselected station by a predetermined amount, circuit means connected to said sensing means for generating a speed control signal to switch said apparatus from a high speed to slow speed in response to sensing the approach to said preselected station by said preselected amount to preclude swinging of the workpiece as the workpiece is brought to a halt, and control means connected to said transfer means for sensing when said workpiece is at the preselected station and stopping said workpiece at said preselected station.
 26. The system of claim 25 further including binary coded decimal limit switches adjacent to said preselected station, address sensing means associated with said workpiece carrier for sensing the binary coded decimal address of certain stations, circuit means for comparing said sensed binary coded decimal station address with the commanded preselected station, said comparison signal being fed to said speed control generating circuit means.
 27. The system of claim 26 wherein said speed control signal generating circuit means includes a slow speed circuit and a fast speed circuit, said slow speed circuit being enabled in response to the sensing of the approaching of said preselected station.
 28. The system of claim 27 wherein said fast speed circuit is enabled prior to the enabling of said slow speed circuit.
 29. A method of operating a control system for an electrochemical workpiece processing apparatus including programming means wherein the workpiece is sequenced through a plurality of work stations in response to commands generated by the programming means, the apparatus including two-speed transfer means, the method including the steps of moving the workpiece in a transverse direction through said work stations, generating a command to direct the workpiece apparatus to transfer to the right or left to a selected station designated by a coded address, sensing when said apparatus has approached a preselected station by a predetermined amount, generating a speed control signal to switch said apparatus from said high speed to slow speed in response to the sensing of the approach of the workpiece to said preselected station by said preselected amount to preclude swinging of the workpiece as the workpiece is brought to a halt, and sensing when said work piece is at the preselected station and stopping said workpiece at said preselected station.
 30. The method of claim 29 further including establishing a binary coded decimal address for each preselected station, sensing said binary coded decimal address, comparing said sensed binary coded decimal station address with the commanded preselected station, and controlling the speed as a function of said comparison.
 31. The method of claim 30 wherein said two speed transfer means includes a slow speed circuit and a fast speed circuit, the method including the step of switching from said fast speed circuit to said slow speed circuit in response to the sensing of the approaching of said preselected station.
 32. The method of claim 31 further including enabling said fast speed circuit prior to the switching to said slow speed circuit.
 33. A control system for an electrochemical workpiece processing apparatus including programming means for sequencing the workpiece through a plurality of work stations in response to commands generated by the programming means, said programming means generating control commands for commanding control functions in addition to said sequencing functions, the improvement comprising a plurality of relay assemblies each having a coil with two input and two output terminals, means for generating a command in the programming means designating a partIcular relay assembly, means for generating a command in the programming means designating one of the two output terminals of the relay means, and circuits means producing a first composite output signal from said relay and said terminal designating signals having a first polarity in response to sensing said relay and said terminal designating command designating said one terminal, said circuit means including means for generating a composite output signal of opposite polarity to said first signal in response to a command designating said relay and a second output terminal.
 34. The system of claim 33 wherein said particular relay assembly generating means includes a bistable circuit and a decoding gate, said decoding gate sensing an alpha-numeric character designating the particular relay assembly, the output of said gate being connected to said bistable circuit, said bistable circuit being set as a function of the sensing of said alpha-numeric character.
 35. The system of claim 34 wherein said output signal producing circuit means includes first and second and-function gates, the input circuit of said and-function gates being connected to the output of said bistable circuit means.
 36. The system of claim 35 wherein said terminal generating means includes a monostable circuit and a decoding gate, said decoding gate being connected to said monostable circuit to produce an output pulse from said monostable circuit in response to the sensing of said particular terminal by said decoder gate.
 37. The system of claim 36 wherein the input circuit of said and-function output gates are connected to the output of said monostable circuit, said output signals being generated in response to the generation of said pulse from said monostable circuit means. 